OK I'll take a look at that.

Right now I am happy with simply closing the vents...they hadn't put out warm air in some time, and the upper vents are, so all is well.

This will be my next project, maybe I'll even take some pics to share as this seems to be a common issue.

I'm not going to touch the back window...when it comes to the point that most of the defroster elemts have perished, I'll simply take it to a shop and replace it, along with the seal, which I suspect leaks under a torrential rain anyway.